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RRM:An incentive reputation model for promoting good behaviors in distributed systems

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Science in china(Series F) 2008年第11期51卷 1871-1882页

作者： ZHANG Hong1.2,DUAN HaiXin1.3 & LIU Wu1.3 1.tsinghua National Laboratory for Information Science and Technology,tsinghua University,beijing 1.0084,china 2 Department of Computer Science and Technology,tsinghua University,beijing 1.0084,china 3 network research center,tsinghua University,beijing 1.0084,china 1. tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China 2. Department of Computer Science and Technology Tsinghua University Beijing 100084 China 3. network {1. center Tsinghua University Beijing 100084 China

Reputation systems represent soft security mechanisms that complement traditional information security mechanisms. They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors. This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model （RRM） for the distributed reputation systems. The objective of this reputation model is not only to encourage the users to provide good services and, therefore, to maximize the probability of good transaction outcomes, but also to punish those adverse users who are trying to manipulate the application systems. The simulation results indicate that the proposed reputation model （RRM） could effectively resist against the common adverse behaviors, while protecting the profits of sincere users from being blemished by those adversaries.

关键词： reputation model distributed system trust soft security

Theoretical research progress in new-generation Internet architecture

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Science in china(Series F) 2008年第11期51卷 1634-1660页

作者： WU JianPing1.2,3,LIU Ying2,3 & WU Qian2,3 1.Department of Computer Science,tsinghua University,{1.,china 2 network research center,tsinghua University,{1.,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,{1.,china 1. Department of Computer Science Tsinghua University Beijing 100084 China 2. network {1. center Tsinghua University Beijing 100084 China 3. tsinghua National Laboratory for Information Science and Technology (TNList) Beijing 100084 China

Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973 Project ＂research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.

关键词： new-generation Internet network architecture multi-dimension scalability

A formal method to real-time protocol interoperability testing

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Science in china(Series F) 2008年第11期51卷 1723-1744页

作者： WANG ZhiLiang1.3,YIN Xia2,3 & JING ChuanMing2,3 1.network {1. center,tsinghua University,beijing 1.0084,china 2 Department of Computer Science and Technology,tsinghua University,beijing 1.0084,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,beijing 1.0084,china 1. network {1. center Tsinghua University Beijing 100084 China 3. tsinghua National Laboratory for Information Science and Technology (TNList) Beijing 100084 China 2. Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.

关键词： protocol testing interoperability testing real-time testing test generation timed input output automata(TIOA)

A TTCN-3-based protocol testing system and its extension

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Science in china(Series F) 2008年第11期51卷 1703-1722页

作者： YIN Xia1.3,WANG ZhiLiang2,3,JING ChuanMing1.3 & SHI XinGang2,3 1.Department of Computer Science and Technology,tsinghua University,{1.,china 2 network research center,tsinghua University,{1.,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,{1.,china 1. Department of Computer Science and Technology Tsinghua University Beijing 100084 China 3. ]tsinghua National Laboratory for Information Science and Technology (TNList) Beijing 100084 China 2. network {1. center Tsinghua University Beijing 100084 China

The protocol testing technology used in the next generation Internet should satisfy some new challenges and requirements. This paper focuses on the test suite description and test implementation techniques. TTCN-3 is chosen as the test suite description language and extended in both syntax and semantics to satisfy the requirements of protocol robustness testing. PITSv3, a protocol integrated testing system based on TTCN-3, is developed, and the extensions for robustness testing are implemented. Finally, two practical test applications are presented.

关键词： protocol testing TTCN-3 PITSv3 robustness testing

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1. GONG Qin~1.and YE Datian~2**(1. Department of Biomedical Engineering, tsinghua University, {1., china 2. research center of Biomedical Engineering, Graduate School at Shenzhen, tsinghua University, Shenzhen 51.055, china) [a]Department of Biomedical Engineering Tsinghua University Beijing China [b]research {1. of Biomedical Engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

A preliminary study on vegetation-erosion dynamics and its applications

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Science china Earth Sciences 2005年第5期48卷 689-700页

作者： WANG Zhaoyin 1.2 , WANG Guangqian 1., LI Changzhi 1.& WANG Feixin 1.1. Department of Hydraulic Engineering, tsinghua University, {1., china 2. International research and Training center on Erosion and Sedimentation, {1., china 1. Department of Hydraulic Engineering Tsinghua University 100084 Beijing China 2. International research and Training {1. on Erosion and Sedimentation 100084 Beijing China

Vegetation-erosion dynamics is a new interdisciplinary science, studying the laws of evolution of watershed vegetation under the action of various ecological stresses. Introducing a qualitative expression of ecological stresses in this paper, the present authors establish the cou- pled differential equations for the vegetation-erosion process and derive a theoretical solution. The model is applied to the Anjiagou watershed on the Loess Pateau and the Xiaojiang water- shed and its sub-watersheds on the Yunnan Plateau. The calculated results agree well with the vegetation development processes. Abstracted from the differential equations the so-called vegetation-erosion chart is worked out, with which we can predict the development trend of vegetation under no human stresses. It is demonstrated that the erosion control is important for vegetation development and reforestation must be a long-term strategy. On the Yunnan Plateau with relatively high precipitation and temperature, vegetation can be greatly improved if erosion is controlled. On the dry and cold Loess Pateau suffering from high rate of soil erosion, however, vegetation can effectively control erosion but erosion reduction exhibits low effectiveness on vegetation development. Vegetation in the area is not stable and management is always needed to maintain the vegetation.

关键词： vegetation-erosion dynamics, human activities, coupled differential equations, erosion control, vigor ofvegetation.

A preliminary study on seismic design criteria of offshore platforms in Bohai Sea of china

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 223-231页

作者： Peng Yanju1.Lu Yuejun1.Yan Jiaquan2,Tang Rongyu1.Wang Junqin3 and Li Jiagang3 1. Institute of Crustal Dynamics,china Earthquake Administration,{1. 1.0085,china 2. Institute of Geophysics,china Earthquake Administration,{1. 1.0081.china 3. {1. research center of china National Offshore Oil Corp.,{1. 1.0027,china Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China

This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 200 and 1.00 - 2500 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.

关键词： fixed offshore platform seismic design level seismic design objective return period Bohai Sea

A Middleware-based Distributed Management Framework for Next-generation network

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计算机工程 2002年第S1期28卷 62-66页

作者： ZHANG JinxiangWU JianpingWANG Jilong(network {1. center of tsinghua University,beijing 1.0084,china) network {1. center of tsinghua University Beijing 100084China

As the basis for next-generation application middleware, distributed computing technique is increasingly used in the network management to fulfill the integration of diverse management systems. Furthermore Web technology is widely used in interaction friendly with user. This article puts forward a MNMI (Middleware-based network Management Integration) framework in the domain of the management of IPv6 test bed-NSFCNET (National Natural Science Foundation of china network). The framework uses a logically-layers method from user interface to managers and pseudo-agent, which uses distributed management and groups managed objects to retrieve, and thus it has assured the performance of network management by providing multiple object quick access.

关键词： network managementCORBAWebFramework

New evidence for lack of CMB power on large scales

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 567-570页

作者： LIU Hao1.& LI TiPei1.2,3 1.Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, beijing 1.0049, {1. 2 Department of Physics & center for Astrophysics, tsinghua University, beijing 1.0084, {1. 3 Department of Engineering Physics & center for Astrophysics, tsinghua University, beijing 1.0084, {1. 1. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Department of Physics & Center for Astrophysics Tsinghua University Beijing 100084 China3. Department of Engineering Physics & Center for Astrophysics Tsinghua University Beijing 100084 China

A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum of the cosmic microwave background (CMB) is derived. The amplitudes of the low multipoles (low-l) measured from the preliminary Planck power spectrum are significantly lower than those reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.

关键词： cosmology cosmic microwave background data analysis